Hi, I don't know if this is the right place, but I figured there'd be people here who know a thing or two about the said calculator model. My TI-86 is and old one (ca. 5 years). I didn't use it in the summer, and when I took it out again, there were multiple dead lines on the LCD screen. Is this a common problem with a calculator as old as mine? Can I do anything about it? Thanks for your help.